South Georgia is home to 25 species of native vascular plant (18 flowering plants, 6 ferns and 1 clubmoss) and around 80 species of introduced plant. The mosses, liverworts and lichens are very diverse, with approximately 125 native species of native moss, 85 species of liverwort and 200 species of lichen. Woody species such as trees are absent due to the harsh climate. Furthermore, the South Sandwich Islands, as a result of their harsh climate, isolation and volcanic activity, are home to only a single species of vascular plant, Antarctic hair grass Deschampsia Antarctica.